DAYS 1-5 (APRIL 5-9)
The large scale weather pattern features a typical springtime “omega block” (a configuration of low pressure / high pressure / low pressure from west to east that resembles the Greek letter omega as plotted on a weather map). Here in southeastern New England we find ourselves on the western side of the easternmost trough to start this week, and the corresponding surface low pressure area is centered south of Nova Scotia and will move southward into the waters east of New England today before turning east and moving away during Tuesday. The circulation with this storm system is quite large and has been bringing rain and snow to Maine since yesterday, continuing up there for a while today while down in southern New England only a few patches of light rainfall may make it near the coast and over Cape Cod before pulling away Tuesday. When we get to the middle of the week, the entire configuration will shift eastward and reorganize so we found ourselves on the eastern side of the high pressure ridge. This means dry weather with mildest temperatures away from the coast, which will be influenced by the still-cold ocean water via the development of sea breezes. Abnormally dry conditions are again observed across the region, and with the lack of rain in the forecast, we’re slipping back toward drought again. Also, the dry surfaces and pre leaf-out status of vegetation leave the region very vulnerable to quick development and easy spread of brush fires, especially early this week when wind speeds will be up somewhat.
TODAY: Overcast Cape Cod with a few periods of light rain possible. Mostly cloudy southeastern NH and the balance of eastern MA. Partly sunny elsewhere. Highs 45-50 Cape Cod, 50-55 southeastern NH and eastern MA, 55-60 elsewhere. Wind N 10-20 MPH, higher gusts especially coastal areas.
TONIGHT: Variably cloudy. Lows 35-42. Wind N 5-15 MPH, higher gusts.
TUESDAY: Partly sunny. Highs 50-57. Wind NW 5-15 MPH, higher gusts.
TUESDAY NIGHT: Partly cloudy. Lows 36-43. Wind NW 5-15 MPH.
WEDNESDAY: Partly sunny. Highs 48-55 coast, 55-62 inland. Wind NE up to 10 MPH.
WEDNESDAY NIGHT: Partly cloudy. Lows 37-44. Wind variable up to 10 MPH.
THURSDAY: Mostly sunny. Highs 49-56 coast, 56-63 inland. Wind variable up to 10 MPH with coastal sea breezes.
THURSDAY NIGHT: Mostly clear. Interior lower elevation ground fog forming. Lows 38-45. Wind variable under 10 MPH.
FRIDAY: Mostly sunny. Highs 50-57 coast, 58-65 inland. Wind variable up to 10 MPH with coastal sea breezes.
DAYS 6-10 (APRIL 10-14)
While there are guidance differences, the overall idea continues to support a tendency for a blocking pattern across North America on the large scale. For us here, high pressure centered at the surface to northeast of the region will try to keep low pressure from the west advancing into the region as the upper level pattern nudges eastward with the ridge moving a bit further to the east over the region while the western low pressure area in the block makes its way into the Midwest and tries to send a surface feature eastward. The leaning at this time continues to be toward drier weather with most rainfall being held to the southwest and south of the region. However an easterly flow may evolve at the surface enough to allow some low level moisture in at some point over the weekend, but it’s too soon to be sure of that. A reorganization of the block should again find our area on the dry side of it as we head toward the middle of the month.
DAYS 11-15 (APRIL 15-19)
An overall tendency for blocking continues with our area on the drier side but the mean air flow often from the north and east with no big temperature swings. This will have to be re-evaluated as guidance often struggles with blocking patterns on the large scale.